Most drugs in this category are synthetic versions of substances produced naturally in the body. In their natural forms, these substances help defend the body against disease. For example, aldesleukin (Proleukin) is an artificially made.

Although aldesleukin is produced naturally in the body, its therapeutic form is developed via biotechnology in a laboratory setting.

Aldesleukin is a form of interleukin, a specific kind of biological response modifier that promotes the development of T-cells.

Patients with metastatic melanoma who do not respond well to other therapies may be candidates for treatment with aldesleukin.

Anyone who has breathing problems, fever or chills while being given aldesleukin should check with a physician immediately. Other side effects should be brought to a physician's attention as soon as possible: dizziness, drowsiness, confusion.